Soldier load carriage: An investigation into the load carriage conditioning practices of the Australian Regular Army

INTRODUCTION
Soldiers must carry equipment and move, on foot, over various terrains for long and continuous periods. While the equipment carried is often crucial to mission success and survival, its weight may be a source of risk to the carrier. As physically conditioning soldiers to carry heavy load may present as a risk control strategy, the purpose of this study was to compare current Australian Regular Army (ARA) load carriage conditioning practices with previously established best practice standards for military load carriage conditioning.

METHODS
ARA soldiers and units were selected via purposive sampling and invited to participate in the study. Soldier self-reported participation in load carriage physical training (PT) was captured via online survey. In addition, textual PT programs were requested from training institutions and operational units. On receipt of textual PT programs, relevant data were extracted and each PT session rated from 1 to 4 based on the session’s specificity and value to load carriage conditioning (in accordance with established best practice). A rating for each PT session was determined by reviewing the PT session title, dress, nature of the PT activity, and any clarifying comments to describe the lesson.

RESULTS
Of the 303 survey respondents, 41% (n=126) reported participating in a load carriage PT session in the preceding fortnight. Marching Order was the most commonly reported form of dress (69%) with mean loads carried of 36.3 kg (SD=12.0kg) or 43% body weight (SD=14% BW). Roads (42%) and dirt or grass (39%) constituted the predominant terrains traversed with over 90% of sessions conducted on flat ground or over mild hills. Endurance Marching was the most common activity (60% of nominated activities) with the majority of reported sessions (79%) lasting no more than 2 hours.

The load carriage PT programs of Initial training institutions generally met with best practice evidence. However, only one (25%) of the corps training institutions built on, and progressed, these initial conditioning standards (up to 32 kg for 165 minutes of endurance marching). Two of the four trade training institutions conducted no load carriage specific conditioning over the duration of their course. Among the PT programs obtained from operational units, 50% (n=4) included load carriage specific PT (up to 31 kg for 120 minutes of endurance marching), the remaining operational units conducted no specific load carriage PT session over their PT program durations.

CONCLUSIONS
When viewed through the lense of the Frequency, Intensity, Time and Type of training principle, the load carriage practices of both the survey respondents and the conditioning programs in trade training institutions and operational units achieved limited success in meeting established evidence-based guidelines for load carriage conditioning. These findings suggest that a training gap exists between ARA current load carriage conditioning practices and the load carriage requirements of soldiers and selected army units during field training exercises and on operational duties.